In a country with more than 350,000 churches, motives are as varied as the denominations they target, experts say. According to the Insurance Information Institute, the top reasons for torching a church include the coverup of a burglary, vandalism, and revenge. Racism, insurance fraud, and thrill-seeking are less common.

In fact, church burnings are common. The nation sees 15 to 20 church arsons a month, scattered from Florida to California. [Editor's note: The original version misstated the frequency of church burnings in the US.]

Nearly 1,000 churches burned between 1996 and 2000 nationwide, according to the Bureau of Alcohol, Tobacco, Firearms, and Explosives (ATF). Authorities nabbed about 100 suspects, a pace that has only decreased slightly.

Since the summer of 1996, when a spate of racially motivated Alabama church fires drew national attention, investigators are not much closer to knowing what fuels the church arsonist. Confessions range from the hateful to the mundane: In Suffolk County, Va., an 18-year-old pleaded guilty to torching St. Mary's Catholic Church in October 2005, after stealing a few hot dogs and some sacramental wine in the course of an inebriated evening.

"There is really nothing unusual about the rate of church fires," says Conrad Goeringer, who has written about the issue for American Atheist magazine. "There's a tendency to construct a conspiracy theory or link fires together that are totally unrelated."

The National Fire Protection Association agrees, citing a five-year investigation in the late 1990s by the Department of Justice, which concluded there was no broader racial conspiracy. The motives for church arsons mirrored reasons given by arsonsists for torching homes and businesses, says John Hall, vice president for fire analysis at NFPA in Quincy, Mass.

"Especially with juvenile fire-setting, which applies to most church arson, motive is rarely as grand as the damages," he says.

Still, religious motivation may lie behind the Bibb County fires.

"If you burn a church and nobody's there, then it's not murder, it's a message," says Joe Barnhart, a religious studies professor at the University of North Texas. "Because we do have freedom of religion, consequently it sends a double message: Even as religion binds people together it also often alienates people."

So far, authorities think a local resident is the culprit in the Bibb County fires, someone who would know exactly where the small, out of the way churches are located - all far from the main road. Often a church arsonist is someone the congregation knows, law enforcement experts say.

"There's been many times when those people who are committing the crime lived in the neighborhood and often frequented the churches," says ATF Special Agent Austin Banks. "Definitely, to commit a crime such as this, there's a deep, deep psychological and emotional trauma that's going on in a person. You definitely have deep-seated issues if you're involved in burning a church."